Limited understanding of influenza transmission has been a frequent obstacle during the development of pandemic influenza infection prevention and mitigation strategies. The science is hotly debated, especially the relative importance of transmission via large droplets or aerosols. Clarification of the relative importance of different modes of transmission is critical for the refinement of evidence-based infection control advice and has been called for by the European Center for Disease Control (ECDC), the World Health Organization (WHO), and the US Institute of Medicine. The primary aims of this thesis were to investigate influenza transmission; i) by obtaining data concerning viral shedding and the presence of influenza virus in the near environment of infected individuals and ii) through the exploration of a human challenge model to study transmission. Two major clinical studies have been performed; • Shedding and environmental deposition of novel A (H1N1) pandemic influenza virus. The primary aims of the study were to correlate the amount of virus detected in a subject’s nose with that recovered from his/her immediate environment (on surfaces and in the air) and with symptom duration and severity. Adults and children, both in hospital and from the community, who had symptoms of influenza infection were enrolled. Information about symptoms was collected and samples were taken including nose swabs, swabs from surfaces and air samples. Forty two subjects infected with influenza A(H1N1)pdm09 were recruited and followed up. The mean duration of nasal viral shedding was 6.2 days (by PCR) and 4.6 days (by culture). Over 25% of cases remained potentially infectious for at least 5 days. Symptom scores and viral shedding were poorly correlated. From surface swabs collected in the vicinity of 40 subjects, 15 (38%) subject locations were contaminated with virus. Overall 36 of 662 (5.4%) surface swabs taken were positive for influenza, two (0.3%) yielded viable virus. Subjects yielding positive surface samples had significantly higher nasal viral loads on illness Day 3 and more prominent respiratory symptom scores. Room air was sampled in the vicinity of 12 subjects and PCR positive samples were obtained from five (42%). Particles small enough to reach the distal lung (≤4µm) were found to contain virus. • Use of a human influenza challenge model to assess person-to-person transmission: Proof-of-concept study. The primary aim of this study was to establish that an experimentally induced influenza infection is transmissible. Healthy subjects deemed sero-susceptible to influenza A/H3N2/Wisconsin/67/2005 were intranasally inoculated (Donors) and when symptoms began, further sero-susceptible subjects (Recipients) were exposed to Donors during an ‘Exposure Event’. Subjects were in close contact, e.g. playing games and eating meals together, for a total of 28 hours during a 2 day period. Samples were collected to confirm infection status. Among 24 healthy adult subjects, nine were randomised to the ‘Donor’ group and 15 to the ‘Recipient’ group. Following inoculation 5 out of 9 Donors (55%) developed illness and 7 out of 9 (78%) were proven to be infected. After exposure, 5 out of 15 Recipients developed symptoms and 3 out of 15 were proven to be infected. Three others were found to be non sero-susceptible prior to exposure. The overall attack rate in Recipients was 20% but was 25% after adjustment for pre-exposure immunity. The contact, droplet and aerosol routes of influenza transmission are all likely to have a role. This thesis shows that transmission of influenza via surfaces may be less important than current infection control policies and public guidance documents imply. Air sampling results add to the accumulating evidence that supports the potential for aerosol transmission of influenza. The human challenge model could be used to investigate routes of influenza transmission further and a study funded by the Centers for Disease Control (CDC) is planned.

N,N-Diethyl-m-toluamide (DEET) is one of the most effective and commonly used mosquito repellents. However, during laboratory trials a small proportion of mosquitoes are still attracted by human odours despite the presence of DEET. In this study behavioural assays identified Aedes aegypti females that were insensitive to DEET. The selection of either sensitive or insensitive groups of females with males of unknown sensitivity over several generations resulted in two populations with different proportions of insensitive females. Crossing experiments showed the ‘DEET-insensitivity’ trait to be dominant. In addition to the finding of heritable DEET-insensitivity, unselected culture mosquitoes were shown to change their sensitivity to DEET after brief pre-exposure to the repellent. Female mosquitoes that were sensitive to DEET when first tested became insensitive when retested. Electroantennography showed that mosquitoes that were insensitive to DEET had a reduced response to DEET compared with mosquitoes that were sensitive to it. This was the case both for culture mosquitoes displaying insensitivity to DEET after brief pre-exposure to it, and for the sensitive and insensitive lines selected for several generations. Single sensillum recordings of the selected lines identified DEET-sensitive sensilla in the sensitive line that did not respond to DEET in the insensitive line. This study suggests that behavioural insensitivity to DEET in Ae. aegypti is a genetically determined dominant trait, which can also be temporarily induced by pre-exposure, and resides in changes in sensillum function. These results highlight the necessity for careful monitoring of DEET-insensitivity in the field, and caution when designing laboratory methods for repellency assays.

Background: Although antiretroviral treatment is expanding in sub-Saharan Africa, the World Health Organization advocates for integration of palliative care with HAAR T because pain, other distressing symptoms and complex psychosocial challenges persist throughout the HIV trajectory. Palliative care improves the outcome for patients with HIV and may complement antiretroviral treatment by increasing adherence through better management of side effects from the treatment, providing patient and family-centred holistic care, and giving end-of-life care when necessary. However, integrating what have become two disciplines is challenging. Aim: To study the implications for palliative care provision in the context of changing policy to universal access to HAART for people living with advanced AIDS (PLWA) in Uganda. Research questions addressed in the study included: 1. How do patients with advanced AIDS (stage III and IV) and with palliative care needs and their families experience care delivery and receipt over a period of 8 weeks? 2. How is the morphine roll-out programme among advanced AIDS patients operationalized in Uganda? 3. What are the challenges faced by health care workers involved in delivery and implementation of integrated palliative care for patients with advanced AIDS? 4. What are the views of key opinion leaders on development of palliative care policies in Uganda? Methods: A mixed methods approach was employed. The study comprised of three phases. In phase one, a consecutive sample of 30 newly enrolled patients advanced AIDS (stage III & IV) and their carers were recruited at Hospice Africa Uganda and followed up for 8 weeks. Qualitative interviews were conducted with patients and their carers at one time point and an outcome measure using African Palliative Care Association-Palliative Outcome Scale (APCA-POS) was used to assess changes in their experiences over 8 weeks, following access to palliative care. In phase two, 10 palliative care staff members participated in individual interviews and one focus group to explore the challenges they faced in delivering services to patients. Phase three explored, by the use of interviews with 7 key stakeholders, the broader context of palliative care policy development and opinions about key priorities for the future. Findings: Out of 30 patients, 14 were male and 16 were female. They ranged in age from 18-60 years. The majority of patients were bed-ridden and experienced distressing symptoms related to advanced AIDS and AIDS-defining cancers which necessitated timely palliative care intervention. The key findings of the study relate to the range of physical symptoms experienced by patients and the psychosocial challenges of disclosure and stigma encountered by patients and their families against a backdrop of profound poverty. Palliative care staff indicated two categories which broadly covered the challenges of palliative care delivery to PLWA in Uganda: service-linked and provider-linked challenges. Palliative health care staff and key stakeholders identified strategies to respond to palliative care needs for PLWA across four dimensions: a) partnerships or networking together with stakeholders; b) improving palliative care education; c) raising awareness of palliative care among communities and health care workers; d) advocacy and policies which support and strengthen initiation and expansion of palliative care services to PLWA, including the availability of morphine. Conclusion: The study shows the paramount importance of drawing on patients' and carers' experiences and concerns to shape models of African palliative care. Both palliative care staff and key informants' perspectives highlight successes, barriers and important lessons for palliative care service delivery in Uganda. These lessons have several implications across the dimensions of practice, education, policy and research. Palliative care staff need to work with several key players or stakeholders to address the many psychosocial issues affecting PLWA including support during treatment. The study indicates the need to translate government policies on palliative care into action.

This thesis aims to examine the effectiveness of a mobile phone based SMS game as a learning intervention for the Peer Educators of the Males having Sex with Males (MSM) groups in Kolkata, India. MSM groups are marginalised and are at higher risk of HIV/AIDS, falling under the core groups for the National AIDS Control and Prevention programmes in India. Peer to peer education for behaviour change in HIV/AIDS prevention projects is a bottom up approach to reach out to this marginalised population for HIV prevention. Training is in place for MSM peer educators but research shows gaps in their support and learning needs. This project developed a mobile game based learning tool to address the peer educators’ learning and support needs. Using a participatory research approach a multiplayer SMS based simulation game was developed, deployed and evaluated, using an existing game engine called ‘Day of the Figurines’. In an effort to enhance experience sharing and peer learning the real life experiences of the peer educators were captured and incorporated through a participatory and iterative process as scenarios of the game. A SMS game on mobile phones was chosen to be in keeping with the marginalised, secretive nature of the MSM identity of the peer educators as well as be in keeping with the mobile nature of their work. The SMS game was piloted in Nottingham and Kolkata and the final intervention was deployed and evaluated in Kolkata with a group of sixteen peer educators from MANAS Bangla, a network of community based MSM organisations in Kolkata, India. Evaluation of the game showed it to be useable, relevant to peer education, interesting and entertaining but in some cases slow, uninteresting and confusing. The game play was affected by technical faults but players still exchanged SMS messages with the game and communicated between players using the ‘chat’ feature of the game. Playing the game enabled players to acquire better communication skills and increased confidence, it gave them a feeling of self-efficacy and influenced their work practices. The intervention was instrumental in increasing the peer educators’ critical consciousness, it created a space to address the practical barriers faced by the peer educators by providing dialogic methods for developing knowledge, encouraging and facilitating collaboration, developing communication skills and increasing access to learning opportunities. This research contributes an exploration of peer educators’ problems, evaluation of mobile game based learning and account of participants’ experiences in a mobile-health development context in resource constrained settings.

Background: Hepatitis C virus infection affects more than 170 million people worldwide and is frequently associated with chronic liver disease and hepatocellular carcinoma. No protective vaccine is yet available and the current standard of care, consisting of pegylated interferon alpha and ribavirin, has limited efficacy. Ribavirin is a key component of any effective anti-HCV regimen. However, accumulation of ribavirin in the red cell compartment not only reduces drug efficacy as a result of diversion to extra-hepatic sites but also produces haemolytic anaemia which can lead to dose reduction or discontinuation of treatment. Lipid or polymer based nanoparticles can be used to deliver therapeutic agents, such as drugs or small interfering RNAs (siRNAs) directly to their site of action. We therefore elected to develop new antiviral strategies based on the targeted delivery of ribavirin to hepatocytes, coupled with the identification of new therapeutic targets. In order to inform the rational use of direct intracellular delivery of ribavirin, we enquired whether variation in expression of the ribavirin transporter may determine drug uptake and permit the identification of individuals who would benefit from these alternative approaches to treatment. Aims: The aims of this study were to: • identify host proteins involved in virus replication • demonstrate reduction of viral replication by modulation of host gene expression • develop and test a nanoparticle based system for the delivery of therapeutic molecules, including siRNAs either alone or in combination with ribavirin. • assess the relationship between ribavirin uptake by primary human hepatocytes and expression of ribavirin receptors Methods: A subgenomic HCV replicon system was established to study the virus-host relationship and identify host proteins supporting viral replication by using stealth siRNA. Viral RNAs were in vitro transcribed and transfected into Huh7 cells and expression assessed using engineered GFP as a reporter gene. siRNAs were co-transfected with viral RNAs using a nucleofector. Modulation of host gene expression was measured by both quantitative RT-PCR and protein blotting. Liposomal nanoparticles containing ApoB-100 duplexes were supplied by Lipoxen. Primary human hepatocytes were isolated by a modified two step collagenase perfusion method and cultured on collagen coated plates. HPLC and real time PCR conditions were used to measure and correlate drug uptake and receptor expression respectively. Equilibrative nucleoside transporter (ENT1) gene was analysed by direct sequencing. Results: A JFH1 (HCV genotype 2a) virus based subgenomic replicon system was successfully established. Using this model system, host proteins VAP-A and STAT3 were shown to positively regulate virus replication while ACTN1 had no effect. Liposomes failed to deliver either siRNA targeted at apoB-100 or ribavirin and this was found to be due to structural instability of the delivery vehicle. In contrast, fluorescently labelled liposomes were stable and could be taken up by human hepatocyte cell lines under optimised conditions. A protocol capable of efficient isolation and culture of hepatocytes from human donor was validated. Data from primary human hepatocytes show that ENT1 expression was highly variable in different sets of primary livers and correlated strongly with ribavirin uptake. Strikingly, Huh7 cells did not take up ribavirin despite expressing wild type ENT1. It was also found that interferon alpha does not modulate ENT1 expression and therefore ribavirin uptake, suggesting it to be a highly unlikely mode of synergism between the two drugs. Conclusion: Modulation of host proteins VAP-A and STAT3 inhibited viral replication, confirming that host genes can be used as a potential target to inhibit viral replication. Liposomes used in this study were, however, found to be ineffective vehicles for the delivery of ribavirin or siRNA, as the majority of drug leaked before cellular uptake. Polymer based nanoparticles are currently being assessed for antiviral drug delivery. Variation in ENT1 expression may account for differences in response rate in patients receiving anti-HCV therapy. Results in the Huh 7 cell line suggest that, while ENT1 is necessary, other factors are also required to mediate ribavirin uptake.

Pneumonia is a common diagnosis in general practice and is associated with significant morbidity and mortality. Current estimates of pneumonia incidence in the UK are based on studies more than a decade ago and little is known about longer term outcomes in pneumonia patients. Though much is known about the aetiology of pneumonia and predictors of mortality, an emerging area for research is the relationship between commonly prescribed drugs in general practice and pneumonia. The aims of this thesis were first, to determine overall incidence and mortality for pneumonia and how these vary by socio-demographic characteristics like age, sex, deprivation; and second, to investigate whether statins, angiotensin converting enzyme inhibitors (ACEIs) and gastric acid suppressants like proton pump inhibitors (PPIs) and histamine 2 receptor antagonists (H2RAs) modify the risk of acquiring pneumonia and its prognosis. This study used data from The Health Improvement Network (THIN) database, a longitudinal database of anonymised computerised medical patient records from 330 United Kingdom (UK) general practices at the time of data extraction in 2006. A cohort design was used to determine pneumonia incidence and mortality in the UK. Case-control, case-series and cohort study designs were used to investigate associations between the various drug exposures and pneumonia. The overall incidence of pneumonia was 237 per 100,000 person-years (95 % confidence interval (CI): 235 to 239) and this rate was stable between 1991 and 2003. Pneumonia was more common in men and in children under the age of four years and adults over the age of 65 years. There was an increased incidence of pneumonia with higher levels of socioeconomic disadvantage. Pneumonia cases showed much higher all-cause mortality as compared to the general population, both in the short and long-term and this increase was independent of underlying comorbidity. After adjusting for potential confounders, current prescriptions for statins and ACE inhibitors were associated with a significant reduction in the risk of acquiring pneumonia. Current prescriptions for PPIs were associated with an increased risk of pneumonia. With regards the impact on mortality: the use of statins was associated with a lower risk of short and long-term mortality following pneumonia whereas the use of ACEIs was associated with a decreased mortality risk only in the short-term. No relationship was observed between prescriptions for PPIs, H2RAs and pneumonia mortality. This study shows that caution must be exercised while prescribing proton pump inhibitors especially in patients known to be at high risk of pneumonia. There is also a potential role for statins in preventing pneumonia in at-risk patients and improving pneumonia outcomes but this will necessitate clinical trials to determine adequate dose, duration and safety profiles before any prescribing policy recommendations are made.

There are many surgical implanted devices in current use and all are prone to biomaterial-related infections (BRI) associated with staphylococcal biofilm formation. BRI are usually associated with S. epidermidis or S. Aureus and are characterized by treatment failure and chronicity resulting in reoperation, removal of the implant, and loss of function or death. Staphylococcal small colony variants (SCVs) may be generated by exposure to sublethal concentrations of antibiotics or nutrient limitation which may occur in biofilms. Although the characteristics of S. aureus SCVs have been well studied, little information on SCVs of S. epidermidis and their potential role in BRI is currently available. This study was designed to investigate the biochemical and phenotypic characteristics of S. epidermidis SCVs to further identify characteristics which may contribute to their ability to cause these increasingly important infections. Exposure to two to four times the gentamicin MIC led to the emergence of stable S. epidermidis SCVs, and the ability to produce SCVs was strain dependent. These variants were isogenic by PFGE and less immunogenic by western blotting, and SDS-PAGE analysis of whole cell preparations and cell wall fractions showed altered protein profiles when compared to wild type strains. S epidermidis SCVs were resistant to aminoglycosides such as amikacin and/or netilmicin and they were thiamine and/or menadione auxotrophs. Chemiluminescence assays showed a decreased ATP content reflecting the deficiency in electron transport systems which results in a growth rate – all characteristics similar to those of S. aureus SCVs. Analysis of virulence factor production indicated that S. epidermidis SCVs showed increased lipolytic and proteolytic activity when compared to those of S. aureus. Some S. epidermidis SCVs showed phase variation in exopolysaccharide production which enabled them to be more adherent to uncoated plastic -a property that may also be important for the later stages of development of biofilms. Invasion assays demonstrated that some S. epidermidis and S. aureus SCVs were internalised by HUVECs by a receptor-mediated mechanism which differed from that of the wild type strains. Interaction of staphylococci with HUVECs induced cytokine production but SCVs stimulated production of IL1, IL-6 and IL-8 at lower concentrations than their related wild type parents in the first 6 hours of co-incubation. SCVs were also less damaging to the HUVEC cell line after 24 hours when compared to wild type strains. This study supports the suggestion that a switch to the S. epidermidis SCV phenotype could be a mechanism exploited by the wild type strains to facilitate their survival inside the host. The chronicity and increased antibiotic resistance associated with BRI could in part, be explained by the characteristics of SCVs identified in this study. In particular the ability to survive intracellularly combined with reduced immunogenicity and resulting decreased cytokine production, may contribute to persistence of infection. Although SCVs are resistant to some antibiotics, surviving intracellularly may further protect staphylococci from other drugs which are unable to enter mammalian cells. Resistance may be further enhanced for some strains in biofilms where enhanced polysaccharide production may also limit antibiotic access.

Since discovery H. pylori has been one of the most intensively researched bacteria. Although the majority of those infected remain asymptomatic it can lead to serious diseases which carry significant morbidity and mortality. The most serious complication of H. pylori infection is gastric cancer and one of the most effective ways to reduce the associated mortality is to detect pre-malignant disease, as this develops in a step wise manner. Using advanced endoscopy is one way to detect pre-malignant conditions but due to the variety in endoscopic techniques and mucosal classifications the diagnosis is often dependent on histology. This work aimed to develop simple, accurate classification systems to detect H. pylori associated disease. The sensitivity and specificity of magnification Narrow Band Imaging for detecting H. pylori gastritis was 69% and 67%, intestinal metaplasia 87% and 97% and dysplasia 92% and 98% respectively. H. pylori is also associated with iron deficiency anaemia but the mechanisms remain unclear. In children it has been proposed that H. pylori disrupts iron regulatory mechanisms via the peptide hepcidin but this has not been extensively researched in adults. Serum hepcidin was significantly lower in H. pylori infected anaemic individuals and anaemic individuals without evidence of infection when compared to controls (9-fold, p=0.009 and 5-fold, p < 0.0001 respectively). These results are opposite to data from children, possibly explained by the presence of gastric atrophy. The cellular localisation of ferroportin was different in the H. pylori infected group which could be due to local cytokine production. Gaining a better understanding of this mechanism could aid the development of more targeted investigation and treatment. However, with regards to allergic and autoimmune conditions, there is growing evidence to suggest H. pylori is inversely associated. It is believed that any benefit associated with H. pylori is confined to childhood when the immune system is developing. A significant reduction was seen in IL10+ Tregs (p=0.0029) after successful eradication suggesting the removal of H. pylori may have systemic consequences on the immune system that are still not fully understood. This work has highlighted the use of endoscopic techniques to identify individuals at risk of disease. It has also described the effects of eradication on the immune system which potentially could have implications for individuals with allergic conditions with regards to eradication therapy.

In the human gastric mucosa, an inflammatory response stimulated by H. pylori infection can lead to gastric cancer and peptic ulcer disease. Expression of the i1 active variant of Vacuolating Cytotoxin A (VacA) by the colonising bacterial strain has been identified as an independent risk factor for disease. VacA skews the adaptive immune response towards a regulatory phenotype to promote persistent H. pylori colonisation. In H. pylori-infected individuals, regulatory T cells (Tregs), which suppress inflammation through mechanisms including interleukin-10 (IL-10) production, are thought to play a role in protection against extra-gastric diseases such as multiple sclerosis and oesophageal cancer. IL-10 is an immunomodulatory cytokine which is expressed by several immune cell types including regulatory B cells (Bregs), whose role in H. pylori infection is unclear. Blood was donated by uninfected and infected patients, and those who underwent successful eradication of their H. pylori infection. A flow cytometry antibody panel was developed to quantify the relative frequencies of peripheral blood Bregs and Tregs, and investigate differences according to H. pylori status. Mice were also infected with H. pylori to determine VacA i1 versus i2 differences in the induced regulatory B and T cell frequencies. Stool samples were collected from patients to develop a VacA i-region PCR-based diagnostic test. Results showed that compared to during H. pylori infection, the proportion of IL-10-producing Tregs in the peripheral blood of patients declined after successful eradication therapy. A pilot study in mice revealed B lymphocytes to be another important source of IL-10, and the population expanded after H. pylori infection. In a study of H. pylori-positive, H. pylori-negative and H. pylori-eradicated patients, there were no significant differences in peripheral blood Breg or IL-10+ Breg frequencies. Data from an expanded mouse study using blood and spleen showed that VacA variants in a colonising H. pylori strain did not induce differences in Breg or Treg frequencies 9 weeks after wildtype or mutant H. pylori SS1 infection. The H. pylori 16S gene was successfully detected in stool DNA samples and could be used to determine infection status, but the development of a vacA i-region PCR-based typing stool test was unsuccessful. Previous work in the research group has identified how Treg frequencies are associated with H. pylori infection and disease. While Bregs are capable of producing IL-10 after stimulation, their role in H. pylori infection in mice and humans appears to be limited. The consistency of peripheral blood Treg frequencies in patients from their infected state until two years post-eradication is a start to understanding whether H. pylori-induced extra-gastric protection may also be maintained after eradication. While stool remains a promising resource for non-invasively diagnosing H. pylori infection worldwide, there are strong concerns about contamination and reproducibility which are unlikely to be overcome for use in a clinical setting.

Background: After three decades, Human Immunodeficiency Virus (HIV) continues to pose significant threats globally. The efforts to curb the HIV epidemic have required investment in research, with clinical trials being a major focus, to develop HIV prevention, treatment, and cure interventions. A large portion of such research has been undertaken within low income settings, due to the high burden of HIV and the availability of willing volunteers within this setting. HIV research calls for the implementation of ethical research practice which is informed by policy guidelines. However, current policies are largely informed by inputs from high income countries, and lack the voices of those closely involved in research implementation. In order to contribute to ethics policy development in HIV research, it is essential to involve different stakeholders by exploring their experiences/views on the issue. Existing research in this field has mainly explored experience of recruitment and trial conduct, while very little has been done on trial closure, indicating a significant evidence gap worth exploring. This research therefore sought to illuminate, explore and understand the significant issues regarding the care of HIV positive drug trial participants during closure of HIV clinical trials, within a low income setting, specifically, Uganda. Study aim: The study aimed to explore how care is perceived and enacted in HIV drug trial closure in Uganda, by addressing the following specific objectives: 1. From the perspective of research participants and research staff, to explore the views, opinions and understandings of the ethical/legal/moral post-trial obligations in HIV drug trials. 2. From the perspective of research staff, to explore the experiences, practices and processes related to care for HIV drug post-trial participants in a low income setting. 3. From the perspective of research participants, to explore the experiences of care at trial closure. 4. From the perspective of research participants, to explore the experiences of transitioning from HIV research to care/community. Methodology: The study adopted an interpretive-constructivist approach, and employed a social constructivist grounded theory methodology. The study included a total of 21 trial participants and 22 research staff from three different HIV drug trials, in two Ugandan research institutions. In addition, relevant ethical documents were reviewed from two of the included trials. Data collection and analysis followed the principles of grounded theory, with data collection and preliminary analysis being undertaken concurrently, and earlier data informing subsequent data collection. Data collection strategies included individual interviews, focus group discussions, and key informant interviews. Data was collected over a period of 10 months, from October 2014 to August, 2015. NVivo10 software was used to manage the data. Ethical approval was received from the University of Nottingham UK and The AIDS Support Organization (TASO) Uganda, Research Ethics Committees (RECs). The study was registered with the Uganda National Council for Science and Technology (UNCST), as SS 3608. Permission to conduct the research was granted by the respective research institutions, and written informed consent was received from all respondents. Findings: The findings showed that trial closure was often stressful for HIV positive participants in Uganda, and often resulted in negative psychological, socio-economic and health impacts. The negative effects mainly resulted from being stopped from accessing research related health care, which was of a significantly higher quality, and the inability to find alternative care to match the research standards. The main concerns which arose during the transition process of participants from HIV drug trials to usual care facilities include: the loss of the quality care and valued relationships in research, the need to find and link to alternative care facilities, the need to meet the increased financial needs, and worries about the effects/outcomes of research participation. These concerns demanded a range of additional care and supportive strategies from researchers (and other stakeholders). A conceptual model, the model of ‘Facilitated Transition’ was developed, which summarises the findings of this research and provides a diagrammatic representation of the research findings, showing the links and relationships between the different elements. The research established that the transition of HIV positive trial participants from research to usual care facilities is a process, which appears to consist of three overlapping phases. These phases include: The pre-closure phase which represents events occurring before the actual trial closure but that underpin post-trial care, the trial closure phase which is the active phase of the closure, in which trial participants are prepared and exited from the trials, and the post-trial phase which represents the events occurring after trial participants have been linked to post-trial care facilities until 12 months later. These phases are demarcated by specific time points, which reflect how the transition process evolves, proceeds and concludes. At the various phases of the process, specific concerns (care needs) arise, being influenced by the participants’ previous care experiences and perceptions, plus their health and socio-economic positions. Specific actions are required to proactively facilitate trial participants during these phases. These actions are underpinned by the perceived ethical and moral responsibilities of the researchers, and are principally aimed at establishing a continuum of HIV care and treatment after trial closure, promoting positive care experiences for trial participants during the transition, and enabling the settlement and adaptation of trial participants to care in the public healthcare system. Conclusions: This is the first known study to investigate perspectives on post-trial care among HIV positive trial participants in a low income setting, from those closely engaged in the research process. This study has provided novel contributions in the area of HIV research ethics and post-trial care in general. The study has established that trial closure involving HIV positive participants raises significant ethical, moral and practical concerns in the Ugandan context. The findings further demonstrated that current post-trial care practice does not meet all the care needs of the HIV positive trial participants. Existing ethical recommendations on post-trial care place an emphasis on the need to ensure access to trial drugs and provision of trial results, where as less attention is given to other important aspects, as revealed in this research. To meet the post-trial care needs of HIV positive participants in Uganda, a comprehensive trial closure strategy is required. In addition to the already existing aspects of post-trial care, the new strategy should aim to: (i) address the financial needs of trial participants through financial assessment, support and empowerment, (ii) provide practical support during linkage to post-trial care, and (iii) offer post-trial follow-up to monitor and support the participants. Implementing these recommendations may require involvement of various stakeholders, including researchers, ethics authorities, research funders and donors, public healthcare workers, families, trial participants, and the community. Recommendations for future research: Further research is required to ascertain the rates of linkage to care, and to assess the health outcomes of post-trial participants following trial exit. In addition, a study to target the views of other stakeholders, such as the public healthcare facility workers, the family, and ethics authorities on post-trial care may be essential to understand better the ways in which to support HIV positive trial participants in Uganda. Furthermore, a longitudinal prospective study on a larger sample is required to test the model proposed in this research. And finally, there is need to deliberate more on the ethical and moral implications of financial benefits in HIV research involving HIV positive participants in a low income setting.